Burden and economic impact of RSV hospitalisations among English adults, 2023/24.

OBJECTIVES: To provide updated, national estimates of the burden and secondary-care costs of respiratory syncytial virus (RSV) hospitalisations among adults aged ≥40 years in England, using data from 2023/24, the last season before the UK implemented its adult RSV vaccination programme, given that, while the burden of RSV is well established in young children and older adults, it remains less well characterised in working-age adults. METHODS: We analysed adults admitted to hospital with an acute respiratory infection (ARI) using aggregated Hospital Episode Statistics (HES) data for England, 2023/24. RSV, influenza, and COVID-19 hospitalisations were identified using validated International Classification of Diseases, Tenth Revision (ICD-10) codes. Incidence proportion was calculated per 100,000 population by age group. To adjust for potential under-recognition of RSV among ARI admissions without an identified pathogen, proportional-redistribution methods were applied. Hospital costs were estimated using Healthcare Resource Group (HRG) emergency tariffs weighted by clinical presentation. RESULTS: In 2023/24, 803,088 ARI admissions occurred among adults ≥40 years; 18% had a viral and 79% an unspecified aetiology recorded. RSV accounted for 4836 admissions (16 per 100,000 population) based on primary diagnosis. After proportional redistribution to account for under-recognition, this increased to an estimated 23,407 admissions (75.9 per 100,000 population; £68.5 million), which we consider the base estimate. In an expanded scenario including all recorded diagnoses, RSV admissions were estimated at 25,264 (82 per 100,000 population; £74 million), of which approximately £54 million may be attributable to unrecognised cases. Around one-third of total estimated RSV-related costs occurred in adults aged 40-74 years. RSV incidence increased steeply with age, reaching its highest levels in adults aged ≥85 years. CONCLUSIONS: RSV poses a substantial, under-recognised hospital burden in English adults and associated healthcare costs. Increased testing and improved coding and surveillance, particularly for adults aged 40-74 years, are needed to accurately measure potential impact of vaccination and guide prevention policy.